Automatic message accounting system



5 She-etg--Sheet 1 G. A. LocKE ETAL AUTOMATIC MESSAGE ACCOUNTING SYSTEMma www@ v June 1.6, 1953 Filed rg. 27. A194'? TM, v

June 16, 1953 G. A. LOCKE EVAL I -AUToMAT MESSAGE AccoUN'rm sys-'rmFiled Feb. 27.1947 5 sheets-Shed `2 QN Aw A #fsk als# June 1611953 G. A.LocKE ETAL 2,642,493

AUTOMATIC MESSAGE ACCOUNTING STSTEMv v Filed Feb. 27. 1947 s.sheets-sheet 5 LINE ,1MPLIFIER nerr/nen Puur cgncu/r GWR/ER Ml.' IFIERSTART 'MWF/5R IHII j.

G. A'. Loc/(E /NvEA/rons WEA VER ATTURNEV June 16, y'1953 G; A. Locke Em2,642,493

I AUTOMATIC MESSAGE ACCOUNTING SYSTEM I Filed Feb, 27. 1947 5Sheets-Sheet 4 By WEQVER ATTORNEY G. A. LOCKE ET AL AUTOMATIC MESSAGEACCOUNTING SYSTEM June 16, 1953 5 sheets-sheet 5 Filed Feb. 27. 1947 L Hi MESA k @Amc/(E .'NVENZIQPS .WEA VER ATTORNEY Patented `lune 16, 953

AUTOMATIC MESSAGE ACCOUNTING SYSTEM George A. Locke, Glenwood Landing,and Allan Weaver, Port Washington, N. Y., assignors to Bell TelephoneLaboratories, Incorporated, New York, N. Y., a corporation of New YorkApplication February 27, 1947, Serial No. 731,396

i8 Claims. (Cl. 178-17.5)

ing time-#spaced impulses both for transmitting and for receivingsignals.

AnotherY feature of the invention is a means for controlling a recordingdevice for recording received signals.

Still another feature of the invention is a means whereby the signalingsystem may operate independently of the recording device. Y

These and other features of the Vinvention will be more clearlyunderstood from the accompanying description, the appended claims, andthe drawings, in which:

Fig. 1 shows the transmitting electronic dis tributor and the registercircuits;

Fig. 2 shows the pulse and control circuits of the transmitter and thetransmitting portion of the transmission system;

Fig. 3 shows the pulse and control circuits of the receiver and ythereceiving portion of the transmission system; l

Fig. 4 shows the receiving electronic distributor and the recordingdevice; f

Fig. 5 shows the timing circuit of the recording device; Fig. 5A shows asample of the recording medium withl signals recorded thereon, and

vFig. 6 shows how the above iigures should be placed with relation toone another to completely disclose the invention ,1

An electronic distributor of the type employed in the present embodimentof the invention comprises a series of stepping tubes which aresuccessively actuated or triggered by pulses initiated by a source ofoscillations to produce a succession of time-spaced impulses. In thetransmitting distributona combination of the impulses so produced,representing the information to be transmitted, is selected by gatetubes and transmitted by suitable means over an electrical circuit tothereceiver. The receiver comprises a similar electronic distributorproducing impulses in time relationship to the impulses, of theelectronic distributor of the transmitter. The coin-` cidence of eachsignal from the transmitter with an impulse from the electronicdistributor of the receiver actuates one of a series of gate tubes inthe receiver. The combination of gate tubes thus actuated in thereceiver indicates the in-y formation received and is used to control arecording device to record the information. The impulses employed ,for`sending and receiving are of relatively shortk duration but theindication of the gate 4tubes of the receiver is'retained until therecording device has operated. In the present invention, the signalsthus registered by the receiving electronic distributor actuate arecording device to record the signals.

and releasing time of the magnets and the neces= sity of advancing thepaper strip after each `line has been recorded. Means are thereforerequired to control the recording device independently of the signaltransmitting and receiving'means after a group of signals has beenreceived. Nevertheless, it is undesirable to prevent the transmittingand receiving devices'from functioningk to transmit and'register "asecond group of signals rwhile the recorder isrecording a first group ofsignals, as that would further slowdown the operation of the system.Precise timing of the cooperating elements of the system is necessarytoattain the highest operating speed lof the system, and, for thispurpose, electronic means of control are the most effective. The presentinvention discloses a novel arrangement of electronic means wheres bythe operations of the system are accurately regulated to the operatingspeed of the recording device yet the maximum over-all operating time ofthevsystem isattained. r

This feature of the invention will be o more Electronic distributors ofthe type-describedare 3 clearly understood from the detailed descriptionof the construction and operation of the invention which follows.

In the drawings, tubes S0, SI, S2 SN, SNI are the stepping tubes of thetransmitter. Tube S is used to start the action of the transmitter foreach cycle of operations and tube SNI to stop said action. The number ofthe remaining stepping tubes SI, S2 SN is equal to the maximum number ofthe signals which may be transmitted in one cycle of operations of thetransmitter. rihe number of said signals is limited only by the numberof stepping tubes provided. The stepping tubes are shown asdouble-triode tubes but double the number of single-triode tubes couldbe used or any combination of lsingle and single-triode tubes but twoV,or more ,triddes may, of course, be combined in one envelope,indesiijed,Y

or other tubes having suitable characteristicsmay be employed. Tube GI)is used 'for starting the action of the transmitter and is associatedwith the start stepping tube Si). Each of the remaining gate tubes G I,G2 GN is respectively as.- sociated with one of the stepping tubes SI S2SN and the number o f said gate tubes is, therefore, equal to the numberof said stepping tubes.

In the present embodiment of the invention, it isassumed that theinformation tobe transmitted is registered by relays RI, R2 .'RN, onerelay being provided for each of the gate tubes GI, G2 GN. Since eachrelay serves only to complete a simple circuit, it is obvious that othermeans of indicating the information to be transmitted could be employed,such as vacuum tubes or Ymechanically operated contacts. Relay L andtube TL are provided to'lock u p those of relays RI, R2 RN which areoperated to indicate the information to be transmitted, and also gforstarting the action of the transmitter when required to transmitsignals. Other suitable means may, of course, Abe used for this purpose.

The pulse circuit o f the transmitter comprises the tubes DI, OSI, SQI,PGI and PAI. "Tube OSI is an oscillator ofwell-known form. `Tube PGI isprovided to produce Vpulses from the oscillations of tube OSI and tubeSQI- is provided to ensure that the pulses will be sharp and of squareform. Tube DI is for starting and stopping the action of the oscillatorOS-I and tube PAI is a pulse amplifier, iof common form. All of thesetubes may be of any type suitable for the ypurposes intended.Alternately othermeans of producing suitable pulses may be used. Tube C!is a control tube for controlling the operation `of the transmitter.While a double-triode tube is shown, two single-triode tubes may, ofcourse, be used or other suitable type of tube.

In the present embodiment of the invention, modulation of a carrierfrequency isv employed for transmitting the signals from the transmitterto the receiver. 'Ihe signals to be transmitted are passed through asuitable low-pass lter FI, to reduce the superimposed harmonics, to amodulator M adapted to modulate the carrier -frequency of an oscillatorCO or other source of said frequency, for transmission over thetransmission line 5U. At the receiving end of said transmission line, aband-pass filter F2, suitable to the carrier frequency employed, and acarrier amplifier CA areA provided. The rectier tube RC is forrectifying the carrier signal, while the line amplier tube LA isprovided vto amplify the 4 signal after passagethrough a suitablelow-pass filter F3. This method of signal transmission is one commonlyused and the circuits and equipment indicated schematically by boxes areso well known that it is not believed necessary to show and describetheir construction and operation in detail. Other suitable methods andapparatus for the transmission of the signals will occur to anyoneversed in the art, and these may also be employed for the purpose ofthis invention.

Tubes STO, STI, ST2 STN, S'INI are the stepping tubes of `the neciyer,cqrresponding to stepping tubes SI), SIjfS I. SN,` SNI of thetransmitter, and are similarly arranged. The

number of stepping tubes-in the receiver is the l sL rriefas the`.r 1u mber in the transmitter. Tubes .GTL GT2 .GTN are the gate tubes of thereceiver corresponding to tubes GI, G2 GN H o f Ethertransmitter, In thereceiver, no gate --tube'is necessary in conjunction with the startstepping Atube However, in the receiver it is convenient to use gastubes for the gate tubes, although, -ef,,c1,' ,1,1i; s, e ,other typesof tubes having the required characteristics could be used.

Thepulse circuit of the receiver comprises the tubes D2, OS2, SQ2, PG2and PA2 and is similar tothe pulse .circuit Aof the transmitter. vTube.C2 is-the control Ytube .for the receiver, .corresponding to tube CI ofthe transmitter, and .is supplemented by .the limiter tube yLR iand thestart rectifier tube SR for actuating :the control tube C2.

. In its present embodiment, the inventionis used .in (connection with alrecording device-.or perfor-ator of vthe type .disclosed in the `W. W.Carpenter U. S. Patent No. 2,583,086 issued `on January 22, v1952forfrecording .the received sig.- nals. This type of perforator .has -aplurality .of magnets PI, P2 PNeach controllinga punch forpunchinga:hole .or.depression in a paper tape.l The lnumber of said lpunchesshould vbe .equal to the number of gate tubes GTI, ,GT2 Thev.combination of holes .or depressions .punched in a line across thetape by ,one Operation of a combination of said punches records thelinfor,-y mation received Vin Kone cycle of operations ofthe Y receiver.A tapefeed magnet when onerated and released,a s will be subsequently.described, advances the tape to a new position for punching anotherfline ,0f .holes .or `@leer-essions t0 record the .information :receivedin the next cycle of operations of the receiver. vTo QQplSIOl 'theperforator for-reCQrdine-suecessive lines of holes or depressions, atiming ,circuit ,comprising the tl'lbs PTC?, PC, MT. FC and EL end ythe.relays RRI. RRZ andRBr .-iwrovded- All Overlap .tube OI, O2 ON is alsoprovidedfor each .of the magnets PI, P2 PN Ato, ns1 ire that sufficienttime is allowed for the correct operation of the punch or punchescontrolled by said operated magnet or magnets-respectively. While it isconvenient to use gas tubes `forthe overlap tubes, as indicated, othertubes or devices having the desired characteristics could, of course, beused in place of said tubes. lThe vinvention is not limited to useinconnection ywith said perforator nor with any particular recording.device. Any .recording or other device capable of utilizing theindications of the receiver in a similar manner maybe employed.

The information to be transmitted from the transmitting circuit to thereceiving circuit and recorded `by theperforator is registered, as-saidbefore, by operating the Vappropriate combinanation of relays RI, R2RN.v This 4is accomplished by grounding by any vsuitable means theright.

the corresponding combination of the conductors, such as conductors 5Iand 53, to the lower windings of relays RI and RN, respectively. Whenconductor 5IV is grounded, a-circuit is completed from battery throughNo. 3 contactv of relay L, conductor 52, lower winding of relay RI, and

conductor 5I to ground, operating relay RI.

When conductor 53 is grounded, relay RNris operated in a similar manner.When the desired combination of relays is thus operated, conductor `54is momentarily grounded by any suitably means, operating relay L over anobvious circuit. The operating circuits of relays RI, R2 RN are therebyopened at No. 3 contacts of relay L, but those of said relays which wereoperated are locked up. For example, if relay Ri is operated, it islocked up over a circuit extending from battery through its upperwinding and No. I contacts, conductor 55, and No. 4 contacts of relay Lto ground. Other operated relays R- are similarly locked to ground onthe No. 4 contacts of relay L.

The No. 2 contacts of relay L connect positive battery through the lowerwinding ofsaid relay to the anode of locking tube TL. .'Ihe No. Icontacts of relay L connect negative battery to condenser 56, chargingsaid condenser through resistance 51 to ground. The charging currentmakes the left control grid of control tube CI momentarily morenegative. Said control grid is so biased by positive battery throughresistances 59 and 60 and negative battery through resistance 5B thatthe left triode of said tube normally conducts over an obvious circuit.The right control grid of said tube is so biased byv positive batterythrough resistances 6I and 52 and negative battery through resistance 63that the right triode does not normally conduct. By the operation ofrelay L, as described above, the left control grid of tube CI is madesufficiently more negative to arrest conduction in the left triode ofsaid tube. The resultant rise of positive potential at the left anode istransmitted through resistance 62 to the right control grid, raising thepotential of said control grid sufciently to permit the right triode toconduct. The resultant reduction of positive potential at said rightanode transmitted through resistance 60 to the left control gridprevents the possibility of the left triode starting to conduct again,the charging time of condenser 49 slightly delaying the reduction ofpositive potential at the left control grid until the pulse fromcondenser has decayed. Conduction in the control tube CI, therefore,suddenly shifts from the left triode to the right triode. This action,familiar to everyone versed inthe electronic art is commonly known astriggering to A similar action, in which conduction suddenly shifts fromthe right triode of a tube to the left triode is known as triggering tothe left. As these actions occur frequently in the circuits of thepresent invention, the above terms will be used in order not to undulylengthen thedescriptiom and it isY to be understood that an action soindicated is similar to that described above fortube CI.

The increase of positive potential` at the left anode of tube CIconsequent upon the cessation' of conduction in the left triode of saidtube is transmitted through resistance 'I0 to the control grid of thelocking tube TL causing the lat- 6 contacts and lower winding of saidrelay and the anode-*cathode space of said tube to ground.

The rise 'of positive potential at the left anode of tube CI is alsotransmittedover' conductor 53, producing a pulse of positive potentialfrom condenser 94 to the right control grid of tube S0 with an effectwhich is described later.

The control grid of the deactivate tube DI is so biased by positivebattery through resistances 59' and 54 and by negative battery throughresistance 65 that said tube normally conducts over a circuitl extendingfrom battery through resistance 65, the anode-cathode space ofspaidtube, and resistance 6l' to ground. The cathodes of the squaring tubeSQI are, therefore, at positive potential. Positive batterythroughresistances 59 and t3 and negative battery through resistance 59 alsobias the left! control grid of the oscillator tube OSI so that the leftanode of said tube conducts through inductance 'II to ground, chargingcondenser 'l2 and supplying positive potential to the left control gridofthe squaring tube SQI. This potential is, however, insufficient tocause the left triode of tube SQI to conduct vso long asy the cathodesor said tube are maintained at positive potential by the deactivate tubeDI.

When, however, the control tube ,CI triggers to the right, as describedabove, the decrease of positive potential at its right anode transmittedthrough resistance 58 to the left control grid of the oscillator tubeOSI arrests conduction in the left triode of the latter tube. The energystored in condenser l2, discharging through inductance 'I I, sets uposcillations which are transmitted to the' right control grid of tubeOSI, in the right triode of which they are amplified. A portion of theamplified oscillations is fed backI from the right cathode of tube OSIthrough potentiometer 13 to inductance 'il to sustain oscillation. Saidpotentiometer is adjusted so that oscillations of nearly constantamplitude are sustained for the period required by one cycle ofoperations of the transmitting and receiving circuits hereinafterdescribed. v

The drop in positive potential at the right anode of control tube Clwhen said tube triggers to the right' is also transmitted throughresistance 64 to condenser 'I4 which is thereby partially discharged,lowering the potential of the control grid of the deactivate tube DI sothat said tube ceases to conduct, Athereby removing the positivepotential from the eathodes of Athe squaring tube SQL The first negativehalf-cycle of oscillations from the left cathode of tube OSI to the leftcontrol grid of the squaring tube SQI has no material effect upon thelatter tube, merely making said control grid more negative. The positive'potential of the next half-cycle, however, causes tube SQI to triggertothe left (the right triode of said tube being normally conducting).The consequent rise of positive potential at the right anode of saidltube produces, through Acondenser l5, a positive pulse at the leftYcontrol grid of the pulse generator tube PGI. Said control grid is 'sobiased .by positive battery through resistance K 754 that the lefttriode of tube PG! normally conducts over an obvious circuit. Thepositive pulse, therefore, has no material effect upon tube PGI. Onthenext negative half cycle from tube osi, the left control grid of tubesQi is made more negative so that said tube triggers tov the right,producing a'n'egative pulse through condenser 'I5 to the left controlgrid of tube 9. nente, and through potentiometer IIlB to ground. Aportion of the energy from potentiometer |08 is conveyed to the controlgrid of the line amplifier tube LA, and an amplied signal is thusobtained from the cathode of said amplier tube.

The ampliiied signals are transmitted over conductor |08 throughresistances, such as resistance I II), to raise the potential of thecontrol grids of the gate tubes GTI, GT2 GTN, and are also transmittedto the left control grid of the limiter tube LR. The latter tube is acathode follower, both triodes of which normally conduct vover obviouscircuits. Each positive pulse thus applied to the left control grid ofsaid tube increases conduction in the left triocle with a consequentincrease in the potential of the cathodesjwhich causes a fall in theconduction of the right triode and an increase of the potential of theright anode due to the ohmic resistance of resistor I I I. The chargingand discharging of condenser H2 to ground through resistance II3 by theresultant :changes in the potential of the right anode of tube LR,producepositive and negative pulses at the cathode ofthe start rectifiertube SR. A part of each negative pulseis rectified byA said tube anddelivered to the left control grid of controltube C2. This tube issimilar to and operates in the same manner as tube CI of the transmittercontrol circuit, normally conducting through its left .triode andnormally nonconducting through its right trode.

Therst negative pulse received at the left control grid of tube C2 isthe result of the decay of the first positive pulse from line amplifiertube LA which, in turn, results from the first carrier signaltransmitted in response to the conduction of gate tube GU. Said negativepulse causes control tube C2 to'trigger to the right in the mannerdescribed for tube CI. The resultant drop of potential at the rightVanode of tube C2 is transmitted through* resistance II4 to the leftcontrol grid of oscillator tube OS2, which, being similar to oscillatortube OSI, thereupon oscillates in the manner already described for thelatter tube. Said drop of potential is also transmitted throughresistance I I5 to the control grid of deactivate tube D2 which issimilar to and operates in the samey manner as deactivate tube DI. Thesquaring tube SQ2, vpulse .generator tube PG2, and pulse amplifier tubePA2 are similar to and operate in a similar manner to tubes SQI, PG2 andPAZ, respectively, in the transmitting circuit, except that the impulsesto pulse-generator tube PGE are taken from the left anode of tube SQZ,Whereas it will be recalled that the impulses to pulse-generatortube PGIare taken from the right anode of tube SQI. In the transmitting circuit,therefore, the rst pulse from pulse-generator tube PGI is produced onthe second negative swing of the oscillator cycle while, in thereceiving circuit, the iirst pulse is produced by pulse-generator tubePG2 on the first positive swing of the oscillator cycle. It will beobserved that control tube C2 is activated bya negative pulse which isthe result of the decay or downward swing of the pulse produced by theconduction of gate tube G0 and transmitted by means of carrier, asdescribed, over line 5I) to the receiving equipment. Gate tube G'is notassociated with any of the register relays'RI, R2 RN and, therefore, thepulse produced by its conduction is not part of the signals representingthe registered information. If oscillators OSI and OS2 are adjusted tooscillate at the same frequency, the first pulse produced bypulse-generator tube PGZ will occur one-half cyclev after' the decay ofthe pulse produced by gate tube G The positive pulses produced bypulse-generator tube PGE and amplified by tube PAZ are transmitted overconductor IIB to the right oathodes of the stepping tubes STO, STI, ST2STN, STNI and aiect said stepping tubes in the same way as the pulsesfrom pulse-generator tube PGI affect stepping tubes S0, SI, S2 SN, SNE,as previously described. VWhen the control tube C2 triggers to the rightas a result of the first negative pulse from the start-rectifier tubeSR, the rise of Vpotential at the left anode of said control tube,transmited over conductor I'I'I, produces a positive pulse fromcondenser II8 to the right control grid of the start stepping tube STO,causing said tube to trigger to the right. A negative pulse is therebyproduced through condenser II9 to the right control grid of tube STIwhich has no material eiect since the latter tube is not conductingthrough its right triode. rst positive pulse from pulse-generator tubePG2 causes the start stepping tube STE) and the stop stepping tube STNIto trigger to the left. A positive pulse is thereby producedthroughcondenser` IIS to the right control grid of tube STI Which causes saidtube to trigger to the right. The rel conduct, nor Vwill vany of themconduct when a positive pulse'is supplied bythe associated steppingtube, asdescribed above, unless, at the same time,. additional positivepotential is supplied from line amplifier LA to the controlgrid overconductor i.

As pointed out above, the rst positive lpulse from pulse generator tubePG2 will coincide with the signal resulting from the conduction of gatetube GI of the transmitter, if the latter tube con-v ducts, in whichevent .a positive pulseV is supplied from line amplifier tube LA overconductor IGS and, through resistance II, to the control grid of gatetube GTI at the same time that a positive pulse is supplied-to saidcontrol grid of this tube Vfrom condenser |20. -Gate tube GTI therebybecomes conducting. If gate tube GI of the transmitter does not conduct,no positive pulse will be supplied from amplifier tube LA to the controlgrid of gate tube GTI of the receiver and said latter tube does notconduct. If gate tube GTI becomes conducting, it conducts over acircuit` extending from positive potential at the cathode of plateopener tube PTO over conductor I23,the,anodecathode space of tube GTIand. resistance -I591 to ground. Being a gas The 11 tube, itcontinues toconduct vafter the positive pulses to its control grid cease.

The next positive pulse from pulse generator tube PG2 causes steppingtube STI to trigger to the left, the resultant rise of potential at theright anode of said tube producing a positive pulse from condenser |25to the right control grid of tube ST2, causing the latter tube totrigger to the right. The effect on gate tube GT2 is similar to thatvdescribed for gate tube GTI. If gate tube G2 of the transmitter isconducting, gate tube GTI conducts and if gate tube G2 is notconducting, gate tube GT2 does not conduct. Successive pulses frompulse-generator tube PGZ successively trigger other stepping tubes,aiecting their associated gate tubes in the manner described above. Acombination of the gate tubes GTI, GT2 GTN is thereby caused to conduct,which corresponds to the combination of gate tubes GI, G2 GN whichconduct. But whereas gate tubes GI, G2 GN conduct but momentarily, gatetubes GTI,GT2 GTN, being gas tubes, will continue to conduct after thetermination of the pulses which cause them severally to becomeconducting.

If relay RR3 is not operated, each of the overlap tubes OI, O2 ON whichis associated with a conducting gate tube GTI, GT2 GTN conducts.V Forexample, if gate tube GTI is conducting, its cathode is thereby madepositive, and positive potential is supplied therefrom to the controlgrid of overlap tube OI, overcoming the negative bias supplied to saidcontrol grid by negative battery through resistance |24. Tube OIthereupon conducts over a circuit extending from positive batterythrough the winding of relay RR2, contacts of relay RR3, conductor |26,winding of magnet PI, and anode-cathode space of -tube OI to ground.Magnet PI operates over said circuit. Other overlap tubes associatedwith conducting gate tubes conduct over similar circuits through thelwindings of their associated punchmagnets, operating said magnets. Acombination of punches is thereby operated which correspondsY to thecombination of conducting gate tubes GTI, GT2 GTN in the receiver,which, in turn, corresponds to the combination of conducting gate tubesGI, G2 GN and to the combination of the operated relays RI, R2 RN in thetransmitter. The relative positions of the. holes or impressions punchedin one line of the tape of the perforator by said operated punches asshown in Fig. 5A, therefore, indicate the information registered byrelays RI, R2 RN. If relay RRS is operated, the' actions described abovewill await the release of said relay. Y

Returning, now, to the transmittingY circuit, when stepping tube SNtriggers to the right in the manner described for stepping tubes SI andS2, the drop of potential'at its right anode vproduces a negative pulsevfrom condenser |05 -to the right control grid of thestop-stepping tubeSNI. Since tube SNI is conducting through its right triode, said pulsecauses said tube to trigger to the left. The increase of positivepotential at the right anode of said tube produces a positive pulse fromcondenser |06 over conductor |01 to the right control grid of controltube CI. This has no material effect since tube CI is already conductingthrough its right triode. When, however, tube SNI is triggered to theright again by a pulse from pulse generator tube PGI, in the same manneras described -for other stepping tubes, the drop-of potential at itsright anode produces a negative pulse from condenser`|0- over conductor|01 to the right control grid of control tube -CI which causes saidcontrol tube to trigger to the left. The consequent rise of potential atthe right anode of said tube, transmitted through resistance 68, raisesthe potential of the left control grid of oscillator tube OSI whichthereupon ceases to oscillate. By the charging of condenser I4 throughresistance 64, the potential of the control grid of deactivate tube DIis also raised so that said tube conducts once more, supplying positivepotential to the cathodes of tube SQI to arrest the action of `saidtube. by pulse-generator tube PGI.

The fall of potential at the left anode of control tube CI, transmittedthrough resistance 10, permits the control grid of locking tube TL tobecome more negative, arresting conduction in said tube and therebyreleasing relay L. The locking circuits of relays RI, R2 RN are therebyopened at No. 4 contacts of said relay and relays RI, R2 RN arereleased,- their respective operating circuits being restored by the No.3 contacts of'relay L. The transmitting circuit is, therefore, restoredto its normal 'condition and is ready for the transmission of anothergroup of signals by another cycle of operations.

Meanwhile in the receiving circuit, relay RRZ operates over the circuitspreviously traced for the operation of magnets PI, P2 PN, completing acircuit from positive battery through resistance |21, contacts of relayRR2, Vand winding ofV relay RRI to ground, over which relay RRIoperates. Tape-feed magnet TF then operates over a circuit extendingfrom battery through the winding of said magnet, conductor 28, andcontacts of relay RRI .to ground. The operation of said magnet, however,has no effect on the perforator, inasmuch as the magnet is arranged tofeed the tape of said perforator only on its release. Y

When stepping tube STN triggers'to the right in the manner described forother stepping tubes, the consequent drop of potential at its rightanode produces a negative pulse through condenser |29 to the rightcontrol grid of the stop-stepping tube STNI, by which the latter tube isnot affected since it is now conducting through its left triode only.But when tube STN is triggered to the left by a pulse frompulse-generator tube PG2, in the same manner as previously described forother stepping tubes, the rise of potential at kits right anode producesa positivepulse from condenser |29 to the right control grid of tubeSTNI, causing the latter tube to trigger to the right. The consequentrise of potential at its left anode, transmitted over conductor |30,produces a positive pulse from condenser ISI to the control grid of theplate-control tube PC, causing said tube, which does not normallyconduct, to conduct over a circuit extending from positive batterythrough resistance |22, the anode-cathode space of said tube, andresistance |32 to ground.Y The positive potential at the anode of saidItube is thereby lowered, lowering the potential of control'grid of theplate-.opener tube PTO which thereupon ceases to conduct and therebyremoves positive potential from conductor |23 and the anodes of the gatetubes GTI, GT2 GTN. All of said gate tubes which are conductingthereupon cease to conduct.

When the stop-stepping tube STNI triggers to the right, as describedabove, theA drop of potential atits right anode is transmitted toconductor No more pulses are, therefore, produced afiliarsey I 33. Anegative pulse is thereby produced from condenser |34 over conductor |35to the right control grid of control tube C2, which causes said tube totrigger to the left. The right anode of said tube thereby becomes morepositive, and this increase of positive potential through resistance II. denser |35 introduces a slight time delay in said action.Pulse-generator tube PG2, therefore, ceases to produce pulses. Thereceiving circuit is now restored to normal and ready for the receptionof signals.

The decreased positive potential on conductor |33, mentioned above, alsomakes the left control grid of the magnet-timer tube MT more negative.

I| also raises the potential of the l Said control grid is so biased bypositive battery through resistances |38 and |35 that the left triode ofsaid tube normally conducts over an obvious circuit, whereas the rightcontrolgrid of said tube is so biased by positive battery throughresistances I and IM and negative battery through resistanceV |42 thatthe right triode of said tubedoes not normally conduct. When the leftcontrol grid is made more negative, as described above, said tube,therefore, triggers to right. The right anode of said tube therebybecoies more negative, permitting condenser |43 to discharge throughresistances |33 and |44. Said discharge produces, through condenser I3?,a positive pulse to theV left control grid of the magnet timer tube MTwhich causes said tube to trigger back to the left after an intervaldetermined by `the capacities of said condensers and the characteristicsof saidY tube. When said tube triggered to the right, the consequentrise in the potential of its left anode produced a positive pulse fromcondenser |45 to the right control grid of the feed-control tube FC. Theleft control grid of this tube is so biased by positive battery throughresistances |55 and mi and by negative battery through resistance |43that the left triode of said tube does not normally conduct while theright control grid is sobiased by positive battery through resistances|139 and |55 and negative battery through resistance |5| that the righttriode normally conducts over an obvious circuit. The positive pulse tothe right triode from tube MT, therefore,A has no material effect.However, when tube MT triggers to the left, a negative pulse is producedfrom condenser |45 to the right control grid of tube FC which arrestsconduction in the right triode of the latter tube and said tube triggersto the left. The consequent rise of potential at its right anode istransmitted through resistance |52 to the control grid of relay tube RL,overcoming the negative bias' The operations of the magnet-timer tubeMT, the feed-control tube FC, the relay tube RL, and

relay RL delay the release of the operated punch magnets, and thecharacteristics of the timing' 7f3 distributor."

- 14 circuit described above are so chosen that said delay is suicientto permit the correct operation of the punches controlled by saidmagnets.

When relay RR2 operates, as previously described, any charge oncondenser |54 is discharged through resistances |55 and |21. When relayRRS operates, as described above, the circuit of relay RRZ is therebyopened and relay RRZ releases, opening the circuit of relay RRI.Condenser ,I5 then charges from positive battery through resista-nce |55and through the Winding of relay RRI to ground. The charging currentholds relay RRI operated for some time, but when condenser |56 ischarged, the charging current ceases and said relay releases, openingthe circuit of and releasing the taper-feed magnet TF which advancesthetape of the perforator to a position for punching a new line of holesorim'- pressions. When on the release of said tape-feed magnet TF thecontacts thereof close, negative battery is applied to condenser |56from which a negative pulse is transmitted over conductor |51 to theleft control grid of the feed-control tube FC, which causes said tube totrigger to the right. The consequent drop of potential at its rightanode is transmitted through resistance |52 to the control grid of therelay tube RL which there,-

upon ceases to conduct, opening the circuit of andv releasing relay RR3.The circuits. are thereby restored to their normal condition. Thus,lafter a group of signals has beenreceived and the punch magnets operatedto record the signals, further operations of the perforator arecontrolled kvindependently ofthe electronic distributors regardless oiwhether or not additional signals are transmitted and received, yet theelectronic distributors -are not prevented from receiving such signals.

The operations described above of relays RRI, RRZ and RRS and tubes FCand RL introduce a delay in the release of the tape-feed magnet TFtransmitting and to ensure that the tape is notv advanced before all ofthe operated punches of the perforator are fully released, and alsointroduces a delay in the release of relay RR3 to ensure that no punchmagnets are reoperated while the tape of the perforator is beingadvanced. For it will be observed that: while the transmitting andreceiving circuits are' l. In a signalling system, in combination, al

first electron tube distributor for transmitting successive groups'ofselected signal impulses, a second electron 'tube distributor responsiveto said rst electron tube distributor to receive said selected signalimpulses, a recording device responsive to said second electron tubedistributor to successively record successive groups of said selectedsignal impulses on a continuous medium, said second electron tubedistributor releasing between said successive groups of signal impulses,and electron tube means initially responsive to each operation of saidsecond electronic distributor for successively controlling the recordingoperationsof said recording device and the position of saidmedium`in`predetermined cycles subsequent to each release of said secondelectron tube 2. In a signalling system, in combination, electronicmeans for producing signal impulses, electronic means for receiving saidimpulses, electronic means for storing selective conditionscorresponding to said signal impulses, a recorder comprising a recordingmedium and magnets, said magnets being responsive to said storing meansfor recording said signal impulses upon said recording medium, means foradvancing said medium, and electronic means responsive to saidelectronic receiving means to release said magnets, to restore saidstoring means after a predetermined interval, and to actuate saidmedium-advancing means at a predetermined interval after the release ofsaid magnets.

3. In a signalling system, in combination, electronic means forproducing successive groups ofV signal impulses, electronic means forreceiving said impulses, electronic means for storing selectiveconditions corresponding to each of said successive groups of signalimpulses, a recorder comprising a recording medium and magnets, saidmagnets being responsive to said storing means for recording a group ofsaid signal impulses upon said recording medium, means for advancingsaid medium, and electronic means responsive to said electronicreceiving means to release said magnets, restore said storing means, andactuate said medium-advancing means while said electronic means forproducing signal impulses is producing and said electronic means forreceiving signal irnpulses is receiving a second group of signal imforrecording the signal expressed by said last-V mentioned electricalconditions, said second electron tube distributor releasing afteroperation to produce said other electrical conditions, and electronicmeans initially responsive to the operation of said second electron tubedistributor for sustaining the operation of said recording devicesubsequent to the release of said second electron tube distributor anduntil all the electrical conditions constituting the signal have beenrecorded.

5. In a signaling system, the combination withk registering meansoperated to register a signal, of a iirst electronic means for producingtimespaced impulses, a rst electronic gating means jointly responsive tosaid operated registering means and to the operation of said rstelectronic means for marking a combination of said irnpulses toYindicate said signal, a second electronic means responsive to said rstelectronic means for producing impulses in time coordination With theimpulses produced .by said iirst electronic means, a second electronicgating means jointly responsive to the operation of said secondelectronic means and to said selected combination of marked impulses forproducing selective conditions indicative of said signal, said secondelectronic means releasing after the operation of said second electronicgating means, a recording device set-` tably responsive to the operationof said second electronic gating means to record said selectiveconditions, and electronic means initially responsive to the operationof said second electronic means for sustaining the operation of saidrecording device'subsequent to the release of said second electronicmeans and until all of said selective conditions indicative of saidsignal have been recorded.

6. In a signaling system, the combination with registering meansoperated to register a signal, of a transmitter comprising a rstelectron tube distributor responsive to said operated registering meansto produce electrical conditions indicative of said signal, a receivercomprising a second electron tube distributor responsive to said rstelectronic distributor to produce selective conditions corresponding tosaid signal, means responsive 'to the operation of said second electrontube distributor for storing said lselective conditions, said secondelectron tube distributor releasing subsequent to the operation of saidstoring means, a recording device responsive to the operation of saidstoring means for recording said selective conditions, and electronicmeans initially responsive to the operation of said receiver forsustaining the operation of said recording device subsequentV to therelease of said receiver and until all of said selective conditions havebeen rec-orded.

7. In a signaling system, the combination with registering meansoperated to register a signal, oi a first electronic means for producingtime-spaced impulses, electronic means jointly responsive to saidoperated registering means and to said rst electronic means for markinga combination of said impulses to indicatesaid signal a secondelectronic means for producingY impulses coordinated in time with theimpulses produced by said first electronic means, electronic gatingmeans responsive to the coincidence of each marked impulse in saidselected combination of marked impulses with a corresponding time-spacedimpulse produced by said second electronic means, electronic storingmeans responsive to the operation of said second impulse producing meansfor storing selective conditions corresponding to said coincidentimpulses and indicative of said signal, said Second impulse producingmeans releasing subsequent to the operation of said electronic storingmeans, a recording device responsive to said electronic storing meansfor recording said stored selective conditions, and electronic meansinitially responsive to said second electronic impulse-producing meansfor sustaining the operation of said recording device subsequent to therelease of said second impulse-producing means and until all of saidstored selective conditions have been recorded.

8. In a recording system, in combination with registering meansrecurrently settable to register a signal, a rst means operative inresponse tof a setting of said registering means for producingvtime-spaced electrical impulses, means jointly responsive to a settingof said registering means and. to the operation of said firstimpulse-producingY means for marking a combination of said impulses toindicate said signal, a second means operative to produce electricalimpulses which are coordinated in time with the impulses produced bysaid iirst impulse-producing means, means responsive to the coincidenceof each marked impulse in said selected combination of impulses withcorresponding impulses produced .by said second impulse-Y producingmeans to indicate said signal, means for storing selective conditionscorresponding to said combination of coincident impulses, a recordingdevice responsive to said storing means for recording said selectiveconditions, and electronic means responsive to said secondimpulse-producuntil all of said stored selective conditions have beenrecorded, said second impulse-producing means being operative during thesustained operation of said recording device under the con trol of saidelectronic means to produce impulses coincident with another selectedcombination of impulses produced by said rst impulse-producing means inresponse to a succeeding setting of said registering means to registeranother signal.

GEORGE A. LOCKE.

ALLAN WEAVER.

References Cited in the le of this patent UNITED STATES PATENTS NumberName Date '2,210,577 Fitch Aug. 6, 1940 2,369,662 Deloraine et al Feb.20, 1945 Number 15 Number Name Date Eisler et al Feb. 19, 1946 Rea et alMay 21, 1946 Smith, Jr. et a1 Oct. 15, 1946 Nichols et a1 July 13, 1948Mumma et a1. Oct. 19, 1948 Cook Mar. 29, 1949 Desch et al Apr. 12, 1949Colt Apr. 19, 1949 Slayton Jan. '2, 1951 Slayton Feb. 12, 1952 SlaytonMay 6, 1952 FOREIGN PATENTS Country Date Great Britain Sept. 14, 1931Great Britain Nov. 22, 1948

